Over the course of the 12th century, the Palaiologoi were mostly part of the military aristocracy, not recorded as occupying any administrative political offices, and they frequently intermarried with the then ruling Komnenos family, increasing their prestige.

When Constantinople fell to the Fourth Crusade in 1204, the Palaiologoi fled to the Empire of Nicaea, a Byzantine successor state ruled by the Laskaris family, where they continued to play an active role and occupied many offices of high rank.

Their rule of the empire continued until 1453 when Ottoman sultan Mehmed the Conqueror conquered Constantinople and the final Palaiologan emperor, Constantine XI Palaiologos, died in the city's defense.

Though Constantine XI died in communion with Rome (and thus as a "heretic"), his death in battle against the Ottomans, defending Constantinople, made the Greeks and the Orthodox church remember him as a hero, redeeming popular opinion of the dynasty as a whole.

As a result, many Byzantine refugees who fled to Western Europe in the aftermath of Constantinople's fall possessed the name and in order to earn prestige, some fabricated closer links to the imperial family.

Various lineages of non-imperial Palaialogoi, whose relation to the medieval Palaiologoi and each other are unclear, survived into the modern period and thousands of people, particularly in Greece, still have the last name Palaiologos, or variants thereof, today.

Through the preceding century or so of Palaiologan marriages to other imperial families, his ancestry could be traced back to the three most recent dynasties that had ruled the empire before the Fourth Crusade (Doukas, Komnenos and Angelos).

[18] In his youth, Michael had served as the governor of the towns of Melnik and Serres in Thrace, and though he and his family were distinguished among the aristocracy, he was frequently mistrusted by the ruling Laskaris dynasty.

[19] Though Michael continued to be mistrusted even after this, he married John III's grandniece Theodora Vatatzaina and was appointed as the megas konostaulos of the Latin mercenaries employed by the empire.

[21] On 25 July 1261, Nicene forces under general Alexios Strategopoulos recaptured Constantinople from the Latin Empire, restoring the city to Byzantine rule after almost sixty years in foreign hands.

In 1284, Michael's son and successor Andronikos II Palaiologos visited the blinded and then 33-year-old John IV during a journey in Anatolia, hoping to demonstrate his disapproval with his father's actions.

The weakening of Byzantium as a result of the civil war allowed Stefan Dušan of Serbia to invade Macedonia, Thessaly and Epirus in 1346–1348, creating the Serbian Empire.

[13] In 1373, John V's son and heir Andronikos IV Palaiologos rebelled against his father in an attempt to seize the throne, instigating a fourth series of Palaiologan civil wars.

[36] In the aftermath of Constantinople's fall, one of the most pressing threats to the new Ottoman regime was the possibility that one of Constantine XI's relatives would secure support and return to reclaim the empire.

Helena had already been married to Lazar Branković, the Despot of Serbia, but the three younger children, and Thomas's wife Catherine Zaccaria, and a retinue of other refugees, accompanied him as he escaped to the Venetian-held island of Corfu.

For 57 years, Constantinople had been under Catholic rule through the Latin Empire and now the easterners had once more asserted their right not only to the position of Roman emperor but also to a church independent of the one centered in Rome.

Some Western pretenders who wished to restore the Latin Empire, such as the King of Sicily, Charles of Anjou, periodically enjoyed Papal support,[56] and several Popes considered the idea of calling for a new crusade against Constantinople to once more impose Catholic rule.

[57] Michael VIII succeeded in achieving a union of the Catholic and Orthodox churches at the Second Council of Lyons in 1274, legitimizing him and his successors as rulers of Constantinople in the eyes of the West.

[78] Though such Palaiologoi, imperial or not, were mainly concentrated in northern Italy, such as in Pesaro, Viterbo, or Venice, other Greek refugees travelled across Europe, many ending up in Rome, Naples, Milan, Paris or in various cities in Spain.

This link gave a certain degree of prominence to several obscure Palaiologoi who had settled in Italy during the late Middle Ages, and was held as an argument that the family had its roots in the city.

[72] Theodore Spandounes mentions a story, according to which the family, originally Romans who arrived in Constantinople in the 4th century, moved to Italy during the exarchate and one of them married in Viterbo.

[88] The earliest record of John's existence other than Theodore's tombstone are the writings of the Greek scholar Leo Allatius, who wrote in 1648, too late for his works to be considered independent evidence.

[91] The absence of any mentions of John Palaiologos in contemporary sources means that the Paleologus family's status as genuine male-line descendants of the last few Byzantine emperors can not be proven, but it is not impossible.

His son Ferdinand Paleologus, escaping the war, settled on the recently colonized island of Barbados in the Caribbean, where he became known as the "Greek prince from Cornwall" and owned a cotton or sugar plantation.

[77] Numerous people with the last name Paleologus are recorded in Venice in the 15th and 16th centuries, many serving as stratioti (mercenary light-armed cavalrymen of Greek or Albanian origin).

Due to his knowledge of the Turkish language, Theodore also accompanied Venetian ambassadors in diplomatic missions to the Ottoman Empire, visiting Constantinople several times.

The Paleologu also live in Malta and France, one of the most famous members of the family being the French diplomat Maurice Paléologue, who in his lifetime repeatedly asserted his imperial descent.

In the 18th century, several Phanariots (members of prominent Greek families in the Fener quarter of Constantinople) were granted governing positions in the principalities of Wallachia and Moldavia (predecessors of Romania) by the Ottomans.

[116] Modern researchers overwhelmingly dismiss the existence of Rogerio as fantasy,[117] given his clearly Italian first name, the unlikelihood of a potential imperial heir being kept as a hostage in Italy and that there are no mentions of such a figure in Byzantine records.

As the Ottoman Empire grew to encompass more and more Byzantine territory, emperors such as John V and Manuel II labored intensely to restore the union, much to the dismay of their subjects.